A corpo



C. I. ROBERTSON. BED MOTION FOR PRINTING PRESSES.

APPLICATION FILED MAR. 25| 1914.

Patented Aug, 1916.

. .u u nu N.

LIQSQQL c. LROBERTSON.

BED MOTION FOR PRINTING PRESSES.. I

APPLICATION FILED MAR. 25| I9I4.

Patented ug. 8, 1916.

2 SHEETS-SHEET 2.

III IIIIIIIIIIIII I II III f FTENT FFIC.

CHARLES J'. ROBERTSON, 0F

TAUNTON, MASSACHUSETTS, ASSIGNOR T0 THE MIEHLE PRINTING PRESS & MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPO- RATION 0F ILLINOIS.

BED-MOTION FOB PRINTING-PRESSES.

ingame.

Specification of Letters Patent.

Patented Ang. 8, 1916.

To all whom it may concern:

Be itv known that I, CHARLES J. ROBERT- soN, a subject of the King of England, residing at Taunton, in the county of Bristol and State of Massachusetts, have invented certain new and useful Improvements 1n Bed-Motions for Printing-Presses, of which the following is a specification. Y The invention relates to mechanism for converting rotary motion into rectilineally reciprocating motion, and is partlcularly designed for use in connection with the reclprocating beds of printing presses, though 1t may be applied and used in any location and for any purpose for which the same 1s adapted.

In order that the principles of the` invention may be fully apparent, I have herein disclosed for illustrative purposes one embodiment of the invention in the accompanying drawings, it being understood that the invention may be carried out by other embodiments thereof and by mechanism widely differing from that herein selected forvillustration. I

In the drawings: Figure 1 is a vertical longitudinal section on line 1-1 of Fig. 2 of a single impression cylinder and a bed cooperating therewith and operated in accordance with my invention; and Fig. 2 is a vertical transverse section along the line 2-2 of Fig. 1 of the type of operating mechanism hereinA selected for illustratiomthe reversing shaft and its outer gear being indicated in elevation, and the impression cylinder and the driven gear carried thereby being diagrammatically indicated by dotted lines.

As shown, the bed of the printing press is' constructed in any suitable manner and operatively connected to mechanism to cause the continuously and uniformly running shaft, irst to propel the bed continuously and at uniform speed in one direction, and then to propel the bed continuously and at uniform speed in the opposite direction, and also to provide for the reversal movement of the bed at the ends of its continuous and uniform movement in each direction by gradually slowing down said movement until the bed is brought to rest and then gradually accelerating its movement in the opposite direction until it acquires the speed of its uniform stroke.

In the usual operation of a printing press of the bed and cylinder class, the bed carrying the type or other printing form is reciprocated in the manner above stated, the peripheral impression surface of the cylinder and paper thereon traveling in theI printing operation at the same surface speed as the form on the bed, so that the paper is pressed against the surface of the form with a rolling action and without any slip of one surface relative to the other along the line of contact between the cylinder and bed. In this class of press the impression is commonly taken only in the travel of the bed in one direction under the cylinder, which continues to run in the same direction all the time that the press is in operation, and after the bed has made its forward and working movement or stroke under the cylinder, the bed must be returned past the cylinder to the starting point preparatory for another working stroke. In the return movement of the bed the. cylinder is commonly raised a little so that its surface is entirely above and clear of the form on the bed, which is now traveling in an'opposite direction to the surface of the cylinder, which thus makes an idle revolution during the return or non-working stroke of the bed. Generally speaking the mechanism for driving the bed' of such class of printing presses comprises a continuously rotating toothed gear and two racks connected with the bed so as to be positioned adjacent opposite edges of the gear and means to cause engagement of one of the racks with said gear to produce the principal part of a stroke in one direction, and to cause the engagement of the other rack with the gear to produce the principal part of the stroke in the other direction, the bed commonly running at uniform speed throughout the part of its strokey effected by the rack and gear, this being the same as the surface speed of the cylinder during the stroke.

When the bed arrives at the end of such rack and gear movement, it comes under the control of another part of the bed motion, which may be termed the reversing mechanism, and which acts to bring the bed to a stop at the end of a short movement beyond the rack traveling movement, and to start the bed in the reverse direction and bring it to the velocity of the rack driven movement by the time that the second rack arrives at and comes into engagement with the gear, at which time the reversing mechanism gives up controland'the bed is again driven by the rack and gear movement to the point near the other end of its stroke, where the reversing mechanism again takes control and performs asimilar reversal of the movement of the bed to that j ust described. That is to say, the reversing mechanism is designed to take the bed at full working speed, reduce its velocity by gradual diminution `until it is stopped and then move it in the opposite direction with a gradual acceleration until it is brought up to full working velocity in said opposite direction. in such type of mechanism the gear and racks may be relatively shifted in many different ways so that the rack and gear meshing teeth used to move the bed in one direction while in ac tion, are out of conflict when the bed is being driven in the opposite direction by the other rack and gear meshing teeth.

My invention is applicable to a gear and rack mechanism wherein the relative shifting of said gear and racks is accomplished by providing the bed with two down-facing racks placed side by side and by using therewith two oppositely rotated' gears shifted into and out of the plane of action of each rack. The particular embodiment of this two gear and two rack device il have illustrated herein7 is one in which the plane of engagement between the top of one gear and itsl rack is at a di'erent clearance level from the plane of engagement-between the top of the other gear and its rack, and one in which the racks are side by side spaced approximately the width of one rack between, and one in whichthe two gears, one double face and one single face, are constantly intermeshed, are simultaneously shifted transversely and in the same direction the one into and the other out ofthe vertical plane of its respective rack and vice versa, that gear which is double-faced meshing into that rack which is at the lower level.

ln the drawings, the bed of the press is indicated at 1 and the impression cylinder at 2, said cylinder being driven in any preferred manner, such for example, as shown .in Fig. 2,A by` a gear 3 at one end thereof,

meshing with a gear L1, upon a reversing shaft 5, mounted in suitable bearings 6, 6,

in the framework of the machine. said framework supporting therein tracks or ways 7, 8, 9, and 10, preferably having sets gfdrpllers 11, 12,y 13 and 14 receiving the The lower face of the bed 1 is provided with racks 15, 16, herein shown both downfacing and vplaced side by side, spaced at least slightly wider than the width of a single rack apart and with the teeth of rack 15 located in a higher horizontal plane than meagre those of rack 16 by an amount at least i through the connecting gears 3, 4, the peripheral speed of bed reciprocating gear 18l is the same as that of the peripheral printing surface of cylinder 2. This double faced bed reciprocating gear 18 is constantly driven by a driving connection with reversing shaft 5 and is so positioned that its top will mesh into and drive rack 16 when shifted into the plane of said rack 16.l Alongside the bed reciprocating gear 18 and intermeshed therewith is an oppositely rotating single `faced bed reciprocating pinion 17, positioned so that its top may mesh into and drive rack 15 when shifted into the plane of said rack- 15. As bed reciprocating pinion 17 is to rotate at the same peripheral speed as bed reciprocating gear 18 it is preferably Adirectly intermeshed therewith as stated.

Since in the present embodimentV of the invention said racks are shown fixed stationary upon the bed and the relative movement between each gear and its coperatng rack is obtained by a shifting movement of said gears, herein shown as a horizontal shifting movement, said gears 17, 18 are so mounted as to bey brought alternately each into working relation with its respective rack, their respective axes being so positioned that the top of -each gear is always in the proper working horizontal plane of the teeth of its respective rack.

In. many-presses where racks are employed whose teeth face each other, the lower rack has been arranged below the large bed reciprocating gear, so that said lower rack engages said gear at the lower edge of the gear. Such a construction is objectionable in that the moving weight on the bed of the press is largely increased by the down hanging length of the parts required vto support the lower rack beneath rthe large bed re; ciprocating gear. Even in those presses where racks are employed whose teeth face each other, both racks passing above the reversing shaft, one of the racks still must be hung down below the bed reciprocating pinion and the support for the bed reciproeating pinion meshing into thisr hung rack `is not easily made as rigid `as desired.

The use for the one stroke of the small adfor the other stroke, allowsjboth racks to 'tance therefrom. Also this construction allows the bed reciprocating pinion 17 to beV solidly supported from the framework of the machine upon both its sides, the absence of down-protruding rack-hanging parts allowing this.

Power may be applied to the machine by many well known means, as for instance by a driving pinion upon a pulley shaft, said pinion (not shown) meshing into gear 4:.

ln the embodiment of the invention shown the double-faced bed reciprocating gear 18 and the single faced bed reciprocating pinion 17, being shifted across lfrom rack plane to rack plane, are shown intermeshed and are shown as being shifted in the same direction at the same time; that is to say, as shown they are shifted together as one. 1n the middle of the double width of the bed reciprocating gear 18, between the two working faces thereof, is an annular groove 19 and on one side of the single face of bed reciprocating pinion 17 is tixed 'a disk 20 whiclntakes into the roove 19 and causes bed reciprocating pinion 17 to shift when bed reciprocating gear 18 is caused to shift. rThe bed reciprocating pinion 17 is here shown mounted to rotate and slide freely upon a fixed stud 21, which stud may be securely fastened upon each side of pinion 17 to the framing of the machine for instance to tracks 8, 9. 1t is evident many diiferent ways of shifting these two gears 17, 18 may be used. When the disk 20 and groove 19 are used to connect them, it is apparent that racks 15, 16 will need to be spaced apart an amount at least slightly greater than the sum of one rack width plus twice the thickness of disk 20, all as shown.

' Bed reciprocating gear 18 is mounted to revolve with and be directly driven by the reversing shaft 5, being positioned concentric to reversing shaft 5 by the drum-like support 22, upon which the bed reciprocating gear 18 is adapted to be shifted by sliding thereupon, axially to itself. 'llhe support 22 may rotate with the reversing shaft 5, in which case the driving feathers 23 may be fixed or integral (as shown) with support 22 and the bed reciprocatinggear 18 would merely slide axially upon and in relation to support 22 when shifted. Again the support 22 may be fixed to bearing 6, in which case the driving feathers23 would be fixed to reversing shaft 5 or to-its crank arm or disk 24 and thegear 18 would rotate upon and not with support 22 and when shifted would therefore slide helically upon and in relation to support 22 but axially as to shaft 5, being guided thus by feathers 23.

Many ways of shiftingI bed reciprocating gear 18 and pinion 17 may be used. The

means shown consist of a continuously rotated cam shaft 25, suitably supported in bearings in the framework and operatively connected to the rest of the machine to make one revolution for each complete movement forward and back of the bed. A grooved cam 26 upon cam shaft 25 swings a double lever 27 by the action of a roll 28 in the cam groove. rlhis double lever 27 may be fulcrumedat 29, 29 on the framework of the press, and by means of pivoted tongue pieces 30, 30 entering groove 19 in -gear 18 will act to shift bed reciprocating gear 18 and pinion 17 bodily together transversely to and fro into and out of the two vertical planes of rack action; disk 20 upon pinion 17, entering groove 19 in gear 18 causing pinion 17 to shift `as gear 18 is shifted as already pointed out.

During the engagement of the pinion 17 with its rack 15 and of the gear 18 with ,its

rack 16, the bed 1 is driven at a uniform -is brought to a stop and then to drive the bed 1 in the opposite direction at a gradually increasing speed until .the working speed of the bed is a ain brought under the control of pinion 1g7 or gear 18 as the case may be. l

ln order'to control bed 1 during the described shifting of bed reciprocating gearY 18 and pinion 17 there is indicated for that purpose in that embodiment of the invention herein shown, reversing gears 31, 31a (Fig. 1) mounted one in each forked end of a slide bar or member 32 having a crosshead 32a receiving therein the crosshead block 33 mounted upon the crank pin 34C projecting from the crank arm or disk or primary reversing element 211 on, and preferably forged or otherwise integral with the reversing shaft 5.

r1`he forked ends of the slide bar or member 32 carry the reversing gears 31, 31a which are constantly in reciprocating mesh with and are rotated by stationary reversing racks 35, 35a suitably mounted upon the framework of the press. The forked ends of the slide member 32 areout-turned and engage with suitable ways 36, 3611 at either side of the stationary racks 35, 35a, thereby to steady the movement of said slide bar 32.

rll`he bed 1 is provided with a short, downwardly facing reversing rack 37, (shown with the teeth removed from lthe central unused portion) with which the reversing gears 31, 31 are alternately brought into en- A gagement by the rotation of reversing shaft 5 and crank pin 34 and the consequent sliding to and fro of slide member 32.

As the bed 1 nears its limit of travel to the right viewing Fig. 1, the bed reversing rack 37 is brought into engagement with the reversing gear 31, at which time the shifting of the bed reciprocating gear 18 and pinion 17 commences, the said reversing gear 31 being rotated because of its meshing engagement with the stationary reversing rack 35 and the crank arm connection with the yreversing shaft 5. The said crank arm connection is such that under the control of said gear 31,'the movement of the bed 1 to the right is gradually reduced to zero and then gradually augmented in the opposite direction until the full working speed of the bed 1 has been secured at which time the bed reciprocatingv gear 18 and pinion 17 have been shifted to bring bed reciprocating gear 18 into driving relationwith rack 16' and bed reciprocating pinion 17 out of driv-y .ing relation with rack 15, the bed 1 then passing from the control of reversing gear 31 to that of bed reciprocating gear 18. As the bed 1 nears the end of its movement in the opposite direction, a similar operation occurs through the instrumentality of the bed reversing rack 37, stationary reversing rack 35a and reversing gear 31a passing lthe control of bed 1 on the return stroke to bed reciprocating pinion 17 and rack 15. While one rack 37 (or two racks close end to end) on bed 1 is shown coacting with two reversing gears 31, 31a on slide member 32, it is obvious these two portions of the bed reversing rack 37 could be sufficiently separated end from end to accommodate the stroke of bed 1 and slide member 32 in such a way that one reversing gear 31 on slide member 32 could co-act alternately with `the two bed reversing racks. e

It -will be apparent from the above der scription that the press herein described has comparatively a small weight of parts reciprocated 'with the bed, that the plane `of travel of such weight may be low down near the floor, and that such bed is free in 4large measure from twisting strains while allowing the center stay of the frame workthat extends across below the cylinder and which has to withstand the bending stresses of the impression to be of unusual height and stiffness. I

Having thus described one specific embodiment of my invention, I desire it to be understood that r`although speciic terms are employed, they'are used in ageneric and descriptive sense and not for purposes of limitation, the scope of the invention being set forth in the following claims.

AI claim:

1. In a printing press, the combination of a bed, a Vdown-facing rack for each direction of bed travel disposed at different clearance levels, a bed reciprocating gear for one direction, a' bed reciprocating pinion oppol sitely rotated and eccentric to and geared with said bed reciprocating gear for the other direction, a connection between the gear and pinion coupling the same together against relative axial displacement, means to slide axially the gear and pinion to and fro together bodily as one, and bed reversing means, substantially as described.

2. In a printingpress, the combination of al bed, a down-facing rack for each directionof'lbedvtravel disposed at different CHARLES J. ROBERTSON.

Witnesses:

BURT D. STEVENS, WILLIS K. HODGMAN, Jr. 

